Correctly handle m68k long double format.
[kopensolaris-gnu/glibc.git] / sysdeps / m68k / fpu / s_nextafterl.c
1 /* s_nextafterl.c -- long double version of s_nextafter.c.
2  * Conversion to long double by Ulrich Drepper,
3  * Cygnus Support, drepper@cygnus.com.
4  * Fixed for m68k by Andreas Schwab <schwab@suse.de>.
5  */
6
7 /*
8  * ====================================================
9  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
10  *
11  * Developed at SunPro, a Sun Microsystems, Inc. business.
12  * Permission to use, copy, modify, and distribute this
13  * software is freely granted, provided that this notice
14  * is preserved.
15  * ====================================================
16  */
17
18 #if defined(LIBM_SCCS) && !defined(lint)
19 static char rcsid[] = "$NetBSD: $";
20 #endif
21
22 /* IEEE functions
23  *      nextafterl(x,y)
24  *      return the next machine floating-point number of x in the
25  *      direction toward y.
26  *   Special cases:
27  */
28
29 #include "math.h"
30 #include "math_private.h"
31
32 #ifdef __STDC__
33         long double __nextafterl(long double x, long double y)
34 #else
35         long double __nextafterl(x,y)
36         long double x,y;
37 #endif
38 {
39         int32_t ix,iy,esx,esy;
40         u_int32_t hx,hy,lx,ly;
41
42         GET_LDOUBLE_WORDS(esx,hx,lx,x);
43         GET_LDOUBLE_WORDS(esy,hy,ly,y);
44         ix = esx&0x7fff;                /* |x| */
45         iy = esy&0x7fff;                /* |y| */
46
47         if(((ix==0x7fff)&&((hx&0x7fffffff)|lx)!=0) ||   /* x is nan */
48            ((iy==0x7fff)&&((hy&0x7fffffff)|ly)!=0))     /* y is nan */
49            return x+y;
50         if(x==y) return y;              /* x=y, return y */
51         if((ix|hx|lx)==0) {                     /* x == 0 */
52             SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */
53             y = x*x;
54             if(y==x) return y; else return x;   /* raise underflow flag */
55         }
56         if(esx>=0) {                    /* x > 0 */
57             if(esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))) {
58               /* x > y, x -= ulp */
59                 if(lx==0) {
60                     if (ix != 0 && hx == 0x80000000) hx = 0;
61                     if (hx==0) esx -= 1;
62                     hx -= 1;
63                 }
64                 lx -= 1;
65             } else {                            /* x < y, x += ulp */
66                 lx += 1;
67                 if(lx==0) {
68                     hx += 1;
69                     if (hx==0) {
70                         hx = 0x80000000;
71                         esx += 1;
72                     }
73                 }
74             }
75         } else {                                /* x < 0 */
76             if(esy>=0||esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))){
77               /* x < y, x -= ulp */
78                 if(lx==0) {
79                     if (ix != 0 && hx == 0x80000000) hx = 0;
80                     if (hx==0) esx -= 1;
81                     hx -= 1;
82                 }
83                 lx -= 1;
84             } else {                            /* x > y, x += ulp */
85                 lx += 1;
86                 if(lx==0) {
87                     hx += 1;
88                     if (hx==0) {
89                         hx = 0x80000000;
90                         esx += 1;
91                     }
92                 }
93             }
94         }
95         esy = esx&0x7fff;
96         if(esy==0x7fff) return x+x;     /* overflow  */
97         if(esy==0 && (hx & 0x80000000) == 0) { /* underflow */
98             y = x*x;
99             if(y!=x) {          /* raise underflow flag */
100                 SET_LDOUBLE_WORDS(y,esx,hx,lx);
101                 return y;
102             }
103         }
104         SET_LDOUBLE_WORDS(x,esx,hx,lx);
105         return x;
106 }
107 weak_alias (__nextafterl, nextafterl)
108 strong_alias (__nextafterl, __nexttowardl)
109 weak_alias (__nextafterl, nexttowardl)